Using cognitive diagnostic modeling (CDM), this study identified subtypes of mathematics learning disability (MLD) based on children's numerical skills and examined the language and spatial precursors of these subtypes. Participants were 99 MLD children and 420 low achievers identified from 1839 Finnish children (966 boys) who were followed from…

This study investigated the development of rapid visual object categorization. N = 20 adults (Experiment 1), N = 21 five to six-year-old children (Experiment 2), and N = 140 four-, seven-, and eleven-month-old infants (Experiment 3; all predominantly White, 81 females, data collected in 2013-2020) participated in a fast periodic visual stimulation…

What processes do infants employ in categorizing? Infants might categorize on line as they encounter category-related entities; alternatively, infants might depend on prior experience with entities in formulating categories. These alternatives were tested in forty-four 5-month-olds. Infants who were familiarized in the laboratory with a category…

Two studies (N = 456) compared the development of concepts of animal species and human gender, using a switched-at-birth reasoning task. Younger children (5- and 6-year-olds) treated animal species and human gender as equivalent; they made similar levels of category-based inferences and endorsed similar explanations for development in these 2…

This study tests the firm distinction children are said to make between living and nonliving kinds. Three, 4-, and 5-year-old children and adults reasoned about whether items that varied on 3 dimensions (alive, face, behavior) had a range of properties (biological, psychological, perceptual, artifact, novel, proper names). Findings demonstrate…

The ability of 1- to 3-year-olds to conceptually interrelate objects was studied among eight children each at 12, 18, 24, 30, and 36 months who were given seven free classification tasks containing a scrambled array of eight objects from two classes. Spontaneous manipulations of the subjects were analyzed. (Author/RH)

Perceptual and categorical similarity were varied independently in a concept-matching task administered to young children. Perceptual similarity proved to be the primary determinant of difficulty level. Superordinate and basic matches were equally difficult. When perceptual resemblance was minimal, most children were unable to recognize matches at…

This study contrasted two possible relations between reflection-impulsivity and analytic or holistic modes of processing. Although impulsive children were more holistic in the classification task, they made more errors than reflectives on matching tests, regardless of whether the content favored holistic processing. (RH)

Three experiments examined the changes in category representation that take place when children use exemplars for tasks other than classification. In Experiments 1 and 2, 6- and 10-year-old children learned to classify exemplars of a novel category and then used the same exemplars in an inferential prediction task. In a subsequent classification…

Despite a large body of research demonstrating the kinds of categories to which infants respond, few studies have directly assessed how infants' categorization unfolds over time. Four experiments used a visual familiarization task to evaluate 10-month-old infants' (N=98) learning of exemplars characterized by commonalities in appearance or…

Previous research suggests that model competence does not emerge until relatively late in infancy (20-26 months). Development was systematically analyzed within 3 key areas--count noun learning, dual representation, and categorization--hypothesized to support the emergence of model competence in the second year. In an object-handling preferential…

Four experiments examined the development of negative priming (NP) in 3-5-year-old children using as a measure of children's executive function (EF) the dimensional change card sort (DCCS) task. In the NP version of the DCCS, the values of the sorting dimension that is relevant during the preswitch phase are removed during the postswitch phase.…

Two experiments investigated the role of the sorting-presentation procedure in promoting organized recall in second grade children. (Author/JMB)

Studies children's inductive inferences in order to investigate the development of the expectation that members of a category share unforeseen properties. Results indicate that preschoolers drew more inferences based on category membership than on perceptual appearances. (PCB)